Not applicable.
1. Field of Invention
This invention relates to food handling equipment, specifically an apparatus that sounds an audible alarm whenever silverware is discarded with food and table refuse.
2. Description of Prior Art
Food preparers involved in restaurants, cafeterias, or catering services that provide silverware to their patrons face potential loss of such silverware during the cleanup process. Such silverware is easily mixed with food and paper refuse such that the silverware is discarded with the refuse. Such silverware is lost both accidentally as it is hidden with other refuse and sometimes deliberately by less than conscientious personnel. Silverware discarded with refuse is a serious problem in this industry.
There are numerous patents that describe devices that use magnets to attract and hold silverware as it flows with paper and food refuse down a chute or into a refuse container. These have no alarms and do not guarantee that lost silverware will be retrieved by less than conscientious personnel. Also, such devices will catch and hold silverware provided the flow and force used on the refuse is within range. Some known patents that deal with such magnetic devices with no alarms are as follows:
Other patents exist that do employ alarms. The applicants are aware of the following references which disclose devices which are more relevant to this area of the art:
U.S. Pat. No. 4,632,253 discloses a chute assembly with an inductive sensor and a flap door having two positions. Such an assembly appears to require a certain amount of cleaning and maintenance to keep the mechanism clean and operative. The power required to move a mechanical flap would likely make this unit less than ideal as far as being portable or having long battery life. Also, since this device senses aluminum and other nonferrous metals, adjustment is required for this device to differentiate silverware from silver paper.
U.S. Pat. No. 4,742,339 appears to overcome some of the limitations of U.S. Pat. No. 4,632,253 in that it uses an alarm to signal the presence of metal as opposed to a mechanical flap to capture such material. However, this invention is reported to trigger on all metal large enough to exceed an adjustable threshold level. Thus, adjustment is required to differentiate between tin foil and silverware. It would appear that larger metal articles whether they be tin foil or metal containers could trigger the circuit.
U.S. Pat. No. 5,538,143 appears to suffer from some of the same limitations as U.S. Pat. No. 4,632,253 in that the device has mechanical doors and a structure that does not lend itself to being easily portable or operating for long periods of time from batteries. The mechanical components appear to require maintenance and periodic cleaning. This device requires calibration to differentiate between cutlery and silver paper.
U.S. Pat. Nos. 5,797,497 and 6,222,450 also disclose metal detectors implying that they would be triggered by metal besides silverware. No differentiation is noted between ferrous and non-ferrous material implying that non-silverware metal in the refuse would likely provide a false trigger.
All current inventions fail to provide an apparatus that detects only silverware while ignoring all other metal, that is truly low maintenance, that is very portable with long battery life, that allows managers confidence that silverware is being detected independent of personnel involved, and that is very affordable due to simplicity of design.
This Silverware Detector consists of a portable sensing mechanism that is installed on the top of a refuse container and can be easily moved from one refuse container to another. It senses magnetized silverware that falls into a refuse container along with other refuse. It ignores all other metal and non-metal objects.
The sensing mechanism uses magnetic field sensors to sense the falling magnetized silverware as it falls through an opening.
An electronic circuit triggered by the magnetic field sensors activates an alarm when silverware is detected.
Accordingly, several objects and advantages of our invention are here provided. Our invention has the ability to differentiate between the silverware of interest and other metal objects be they ferrous or non-ferrous. Only magnetized silverware triggers the alarm providing for a very consistent and reliable means of detection. Also, our invention is mechanically simple with no moving parts that require cleaning or adjustment. Accordingly, our invention is light weight allowing easy movement from refuse container to refuse container. Our invention uses little electrical power allowing long operation on a set of batteries further enforcing our claim of portable operation with little periodic maintenance. The presence of a latched audible alarm allows security features that prevent unconscientious employees from ignoring silverware falling into the refuse container.